Tweak token docs. Add release date.

Author: oschwald

CHANGELOG.md

@@ -1,7 +1,7 @@
 CHANGELOG
 =========
 
-1.2.0
+1.2.0 (2016-11-11)
 ------------------
 
 * Added `/credit_card/token` input. Use the `token(String)` method on

src/main/java/com/maxmind/minfraud/request/CreditCard.java

@@ -127,8 +127,14 @@ public CreditCard.Builder cvvResult(Character code) {
         }
 
         /**
-         * @param token A token uniquely identifying the card. This should not be
-         *             the actual credit card number.
+         * @param token A token uniquely identifying the card. The token
+         *              should consist of non-space printable ASCII
+         *              characters. If the token is all digits, it must be
+         *              more than 19 characters long. The token must not be a
+         *              primary account number (PAN) or a simple
+         *              transformation of it. If you have a valid token that
+         *              looks like a PAN but is not one, you may prefix that
+         *              token with a fixed string, e.g., "token-".
          * @return The builder object.
          * @throws IllegalArgumentException when the token is invalid.
          *